Guest blog by The Coastal Resource Centre, Chennai
This stories of Adyar and Kosasthalaiyar Rivers from Chennai is fifth in the series of online stories of urban rivers from across India. Please share your feedback and provide us with suggestions (read more in appendix). If you have any urban river stories or images that you might want to share, please send them to firstname.lastname@example.org and email@example.com.
The South Indian coastal city of Chennai is home to more than 5 million people. The city is predominantly flat and consists of sandy coastal plains drained by three major rivers the Adyar, Cooum and Kosasthalaiyar. The latter is the largest and empties through a backwater and estuary at the Ennore Creek.
Because of its flat topography, early settlements in the region were possible only after making arrangements to hold rainwater through harvesting structures like Eri’s or irrigation tanks. Surplus from the tank network was designed to drain into rivers and thence to the Bay of Bengal.
Between 1980 and 2010, the built up area inside the city has grown from 47 square km to 402 sq km. During the same period, area under waterbodies declined from 186 square km to 71 square km.
Degrading land-use change and the abuse of the three rivers in the name of urbanisation is a major factor in the city’s increased vulnerabilities to droughts and floods.